FWIW...I NEVER swerve to avoid an animal.
Not just for the previously mentioned reasons, but if I swerve to miss a deer, and hit a tree. I am at fault. If I hit a deer...insurance company pays for damages (less deductable).
To my credit, I have 2 deer, 1 fox, 1 cat at least 6 raccoons, and coutless possum, squirrel, rabbit and chipmunks. Also, 1 pheasant, 1 turkey (small one thankfully) 2 ducks and a few doves. I am not proud of these hits, just a natural hazzard of driving 17 miles each way to and from work thru the Horicon Marsh area. Early morning and early evening. God knows how many time I nailed the brakes to avoid an accident with wildlife. Never did I swerve. If I had, I would have either crossed the center line and hit another vehicle, or gone splash into the marsh or rolled my truck down a hill. Neither one sounds good to me.